There's a great scene in "Far Away Places," Episode 6 of Season 5 of Mad Men, in which Roger Sterling and his wife Jane are about to drop acid at the end of a dinner party at Jane's psychiatrist's house. "How long does it last?" asks Roger.

I could have told him the answer.

I didn't take LSD a lot of times, but by the time I was taking it in the mid-70s, it was illegal. Timothy Leary had spent the latter part of the '60s trying to convince everyone that LSD was the path to enlightenment. That was both understandable and stupid. But I was a kid looking for enlightenment, and acid seemed as promising a path as any.

Actually, I'm not sure why I dropped acid the first time. Yes, I was a kid looking for enlightenment, but I was also a kid looking for thrills, looking for experience, looking to fit it.

But I can tell you this: the party scene in "Far Away Places" is the most accurate portrayal of an acid trip I've ever seen. Being on acid is not like the old movies they showed us in junior high health class, where people transform into devils and half your face melts when you look in the mirror. It's not like the swirling fly's-eye photography you used to see when hippies dropped acid on Dragnet and roasted babies in the oven.

It's like opening a bottle and hearing a symphony. It's like smoking an entire cigarette in one drag. It's like watching yourself across the room dancing with your wife. Time is meaningless, space is distorted. You can't be sure where you end and the rest of the world begins.

"Far Away Places," on the other hand, is divided neatly into three stories, all of which transpire on the same day. Our theme? Control: grasping for it, finding it (fleetingly), fighting for it, losing it, perhaps even giving it up. Every relationship is a power stuggle, and our viewpoint characters are all struggling powerfully.

The first story is Peggy's. She's nervous about her second pitch to Heinz and fights with her boyfriend Abe. Don makes it worse by pulling out of the pitch at the last minute and taking Megan with him. They're off for a last-minute business trip to a new Howard Johnson's in Plattsburg, and Don leaves Peggy in charge.

Bad idea. The client isn't buying, and Peggy insults him. She's frustrated because she's already taken his crappy direction and tried to give him what he wants, only to be rejected again. So she lashes out, telling the client, in so many words, that he's stupid and he should buy what she's selling. It's the same speech anyone who's ever made this sort of presentation has wanted to make, but we understand that it would be, as Stan the art director tells Peggy after the fact, suicide.

So what's a dead girl to do? How about a movie? Earlier, Abe has suggested they see The Naked Prey, and she goes by herself. But a man sitting behind her offers her a joint, and she accepts. Then she jerks him off while he watches the film. Finally, she's in control, having the situation well, as it were, in hand.

After the movie, Peggy washes up and goes back to the office, where she falls asleep on Don's sofa. She's awakened by a frantic call from Don. Peggy assumes he's upset about her behavior in the Heinz presentation--but we the viewers can see that something is clearly, and horribly, wrong.

Then there's truly weird conversation between Peggy and Ginsberg in which Ginsberg tells her that he's actually a Martian. And that he was born in a concentration camp. And that he's not sure he's not the only Martian on Earth. Peggy knows how he feels. She ends her strange-trip-of-a-day inviting Abe over to her apartment, still looking for a genuine connection.

Rewind. It's morning again, and Roger is suggesting to Don that they ditch their wives and take a road trip to the new Howard Johnson's in Plattsburg. Don has a better idea: he'll take Megan so Roger can go to a boring dinner party with Jane.

Only the dinner party turns out to be life-changing. Roger drops acid and embraces his hallucinations. Back home, naked in the bathtub with Jane, he watches the 1919 World Series and laughs with delight. Afterwards, Roger and Jane lie on the floor, red towels wrapped around their heads. They admit to each other that their marriage is over--that each was just waiting for the other to end it. It's a moment of uncommon clarity and tenderness for Roger--and ends with a shot of the two of them in each others' arms, red towels unfurling like pools of blood around their heads.

Rewind. Don, remember, is on a trip, too. The Howard Johnson's is all shiny plastic andNaugahyde, but Megan isn't charmed. She's miffed that she's missing the big presentation; in fact, she's tired of Don always being in charge of her life. "Get in the car! Eat ice cream! Leave work! Take off your dress! Yes, master," she yells. Don drives away, leaving Megan in the parking lot. At last: here's a glimpse of the Don Draper we're known and been conflicted about for four seasons.

Don soon calms down and drives back to HoJo's. But Megan is gone. The waitress tells Don she left with some men, and Don finds Megan's sunglasses on the pavement. He searches the hotel, calls her mother, but turns up no further clues.

Thankfully, Megan is at home. She's understandably furious; she hits Don, and he chases her around the apartment, and not in a sexy way. Finally, Don tackles her and they lie on the floor together, a mirror image of Roger and Jane. "Every time we fight, it just diminishes this a little bit," says Megan. "I thought I lost you," says Don.

And so all three trips to far away places have different endings. Don keeps his tenuous grip on his fantasy. Peggy is still looking for her power spot; one of the episode's final shots is Peggy walking through the office while the rest of the creative team walks in the opposite direction. (Also worth mentioning are the multiple shots of reflections in this episode: Ginsberg in the window, Roger's face in the mirror, Don's image through the conference room glass.)

And Roger? I have news for Roger. "How long does it last?" he asks.

The answer is, forever. Acid changes you. For the better, you hope. But for good.